Field
Embodiments described herein generally relate to methods and systems for processing spent air. More particularly, such embodiments relate to methods and systems for cleaning spent air from a cumene oxidation process.
Description of the Related Art
Phenol and acetone are produced in various processes, the most common of which is known as the Hock Process, the Hock and Lang Process, or the cumene-to-phenol process, among others. This process begins with the oxidation of cumene (isopropyl benzene) to form cumene hydro-peroxide (CHP). The oxidation of cumene can result in the discharge of spent air. This spent air usually contains volatile organic components or volatile organic compounds (VOCs), such as unreacted cumene. Health hazards are typically associated with exposure to VOCs and VOC emissions are subject to governmental regulations.
Industry, therefore, has sought to limit the amount of VOCs emitted from cumene oxidation processes. Current industry practice is to condense the cumene in the spent air from a cumene oxidation process with cooling water and/or refrigeration. The condensed cumene is then separated from any remaining gaseous components. These remaining gaseous components are then typically subjected to thermal or catalytic incineration. Other processes include filtering the remaining gaseous components by adsorption and, if required, subjecting the gaseous components to thermal or catalytic incineration. Incinerating the remaining gaseous components, however, can result in NOx emissions.
There is a need, therefore, for improved methods and systems for removing VOCs from the spent air from a cumene oxidation process.